Culprit in Legionnaire disease has a face now—but still no nameThe persistence and thoroughness of scientists at the national Center for Disease Control (CDC) finally paid off when, after a six-month search, they succeeded in isolating a bacterium believed to have caused last summer's mysterious "Legionnaire disease.""You're never really satisfied until, in your own mind, you've accounted for everything. We weren't really sure we had," says Joseph McDade, PhD, a microbiologist at the CDC.Dr McDade first spotted traces of the odd, slow-growing bacteria on slides made last summer when there was intense pressure to quickly find the cause of the illness that resulted in 29 deaths (JAMA MEDICAL NEWS 236:1001 [Aug 30] 1976).Among the many possibilities considered was Q fever, a rickettsial disease, and Dr McDade's laboratory, under the supervision of Charles C. Shepard, MD, quickly ran a standard series of tests for Rickettsia. Lung